Screening and Characterization of Plant Growth Promoting Rhizobacteria (PGPR): An overview

Abstract

Rhizobacteria are root-colonizing bacteria that have established symbiotic associations with more or less all plants. Rhizobacteria that can enhance plant growth and crop production by various mechanisms like siderophore and phytohormones production, inorganic phosphate solubilization and antifungal activities,are often referred as plant growth-promoting Rhizobacteria(PGPR). These organisms increase the availability of nutrients through the solubilization of unavailable forms of nutrients which aids in nutrient transport subsequently reduces the usage of chemical fertilizers and pesticides. Hence, the application of PGPRs in agriculture is increasing. Overall progress of the plant is fully dependent on the growth promoting compounds produced by these organisms. PGPR can endow with a proficient alternative to the excessive use of chemical fertilizers, pesticides and other supplements routinely used in agriculture. Progress so far, in studying the diversity and characterization of PGPR in the rhizosphere could be a reliable tool for sustainable agriculture and livelihood. To strengthen the application of PGPRs, there is a need to know and understand the methods for their isolation and characterization of PGPR from rhizosphere soil to develop crop-specific bio-fertilizers. At the same time there is a need to understand various biochemical and molecular methods used for the isolation and characterization of PGPRs, which will be discussed in this review. Till now, both biochemical and molecular methods for the characterization of PGPR have not been discussed altogether. This review will also provide a broad spectrum for the various applications of PGPR in sustainable agriculture.